St. Benilde Hall #109
Dr. L. Yu Lin
Fluid mechanics is the study of the way fluids (liquids and gases) behave in systems. Water pressing against the base of a levee, air moving around the wing of a plane, and oil flowing through a pipeline are all examples of systems where an understanding of fluid mechanics is vital.
A wind tunnel creates an artificial breeze and drives it through a chamber where models can be suspended. This allows the study of drag forces and aerodynamic properties. A smoke tunnel is similar, except that injecting smoke into the moving air makes it possible to observe air flow patterns.
Moving liquids through piping systems is an important area of study. Our fluid flow network allows students to apply what they’ve learned by measuring the effect of valves, bends, tees, and other fittings. Flow and pressure sensors make the needed measurements. In order to move the fluid, students need to understand centrifugal pumps or gear pumps. Similarly, gases or vapors are moved through duct systems using centrifugal fans for low pressure systems or centrifugal compressors when higher pressures and volumes are needed.
Work can be extracted from flowing fluids (think of water wheels) using turbines. These are sometimes categorized as axial flow or radial flow turbines, depending on the direction the blades rotate with respect to the direction of fluid flow.
When a fluid flows through a bed packed with small objects or particles, the particles may be suspended in the fluid. These fluidized beds may be used to improve combustion or catalytic reaction efficiency.
While mechanical and chemical engineers focus primarily on flow through pipes and ducts, civil engineers also need to understand open channel flow– like you might see in a ditch or stream. (“Open” means that the flow is not completely enclosed, but has a flowing surface exposed to the atmosphere).
Another key area of engineering study is heat transfer– the study of how thermal energy moves from one place to another. A heat exchanger is a device for transferring heat from one flowing fluid to another. An example is the radiator in a car which transfers heat from circulating hot water to the surrounding air. Common industrial versions are the double pipe and shell and tube heat exchangers, so students can use these to learn how the theory they learn in class might function in real applications. Additional heat transfer equipment is located in the Mass Transfer Lab.